code: def testPrunesForeverIfEndStepIsNegativeOne(self):
      sparsity = pruning_schedule.ConstantSparsity(0.5, 0, -1, 10)
  
      step_10000 = tf.Variable(10000)
      step_100000000 = tf.Variable(100000000)
      compat.initialize_variables(self)
  
      self.assertTrue(self.evaluate(sparsity(step_10000))[0])
      self.assertTrue(self.evaluate(sparsity(step_100000000))[0])
  
      self.assertAllClose(0.5, self.evaluate(sparsity(step_10000))[1])
      self.assertAllClose(
          0.5, self.evaluate(sparsity(step_100000000))[1]
      )
  
imports: from absl.testing import parameterized
  import tensorflow
  from tensorflow_model_optimization.python.core.keras import compat
  from tensorflow_model_optimization.python.core.quantization.keras import utils
  from tensorflow_model_optimization.python.core.sparsity.keras import pruning_schedule
label_desc: Use image node_id 1 for calling the ConstantSparsityTest obj's underlying member method code with example usage: obj.testPrunesForeverIfEndStepIsNegativeOne() without return types